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I'm rather new to electronics, and I'm really in trouble here.

I'm have a bit of a puzzle here, regarding my Rigol DS1052E Oscilloscope. I'm trying to adjust the probes, but I get a wierd result on channel 1.

For both channels I use the same settings:

  • Coupling = DC
  • Bandwidth limit = on
  • Probe = 10x (Also 10x on the actual probe)
  • Digital filter = OFF.

I use the squarewave on the scope as input for both channels, and I use the same (one) probe for both channels.
Channel 2 gives me the expected squarewave with 3 volt signal.
Channel 1 however, gives me 1/5 = 600 mV and the signal is nowhere near a squarewave. See attached photos.

Please give me your advice. If I can assist you with further information, then please feel free to comment regarding this.

Thanks in advance.

Channel 1:

photo of oscilloscope screen viewing channel 1


Channel 2:

photo of oscilloscope screen viewing channel 2


Images on link with pure DC (3.84V) measured with multimeter:
https://drive.google.com/open?id=0B7SZfQswIltgMkszckpuN2lMaEU

Channel 1: 3.84V DC

photo of scope channel 1 with 3.84V DC signal


Channel 2: 3.84V DC

photo of scope channel 2 with 3.84V DC signal

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  • \$\begingroup\$ Hmm, it does look like something really odd is going on there. Channel 2 signal is 300 mV pk-pk, nice square wave. Channel 1 is double that with a not insignificant DC offset, and it looks like a cap charging through a resistor. How do things look with just a constant DC level - both with the probe tip shorted to GND and measuring a battery or similar source? \$\endgroup\$ – alex.forencich Aug 30 '16 at 20:17
  • \$\begingroup\$ Channel 1 looks suspiciously like the probe hasn't been compensated properly. Have you adjusted the capacitance of the probe to get the best result on channel 1? \$\endgroup\$ – helloworld922 Aug 30 '16 at 20:26
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    \$\begingroup\$ That looks like more than probe compensation to me, and I think OP is using the same probe for both channels to try to eliminate any problems with the probe itself. \$\endgroup\$ – alex.forencich Aug 30 '16 at 20:33
  • \$\begingroup\$ @alex.forencich Just uploaded screen dumps as you asked for. \$\endgroup\$ – Lars Hansen Aug 30 '16 at 20:52
  • \$\begingroup\$ @helloworld922 Yes I have tried that. But its noway near squarewave. \$\endgroup\$ – Lars Hansen Aug 30 '16 at 20:53
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Unfortunately, I think the conclusion here is a bad scope input. Probably more likely a front-end problem than a digitizer problem, but it's definitely a hardware issue internal to the scope. It's not the probe because the same probe works fine on channel 2, and it's not a settings issue as a factory reset has been performed.

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Depending on warranty and who owns this, you may need to consult service@rigol.com. with an explanation of two waves , same probe on calibration terminal

Good luck. Looks like front end is partially blown.

Consult manual for self test thru Utility menu

Try 1x switch

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